1. The Field of the Invention
The present invention relates to valves, and, in particular, relates to hemostasis valves.
2. Relevant Technology
Various medical procedures require temporary and often repeated introduction and removal of catheters and/or guide wires within the cardiovascular system of a patient. For example, using only a relatively small incision, a catheter can be introduced into a blood vessel of a patient and used to position a balloon, implant a stent or deliver a fluid directly to a predetermined location within the cardiovascular system. Catheters can also be used for exploratory surgery and for removing tissue samples within a patient""s body, for example.
Operations using catheters can often require the insertion and removal of several different types of catheters and guide wires, which can be employed to guide catheters to a desired location within the body. One problem encountered with the insertion, removal and adjustment of catheters and guide wires is controlling bleeding at the point where the catheters and guide wires are first introduced into the cardiovascular system. In one approach to controlling bleeding and ensuring easy insertion and removal of the catheter and/or guide wire within the cardiovascular system, one end of a hollow introducer is first secured within a large blood vessel of a patient. The opposite end of the introducer is positioned outside the body of the patient and is attached to an adapter.
Such an adapter typically comprises a short, rigid tube having a passageway extending therethrough. Attached at one end of the adapter tube is a connector. The connector is used to connect the passageway of the adapter tube to the exposed end of the introducer. This enables fluids and/or medical instruments, such as catheters and guide wires, to pass between the adaptor tube and the introducer.
Positioned at the opposite end of the adaptor tube is a valve commonly referred to as a hemostasis valve. The hemostasis valve typically includes one or more seals positioned within a valve body. During use of the adaptor, the pressure of the blood of the patient caused by the beating of the patient""s heart can cause blood from the patient to flow through the introducer and into the passageway of the adaptor tube. The one or more seals prevent blood from escaping out of the adaptor through the access of the valve.
Typical hemostasis valve adaptors feature a xe2x80x9cYxe2x80x9d shape or xe2x80x9cTxe2x80x9d which enables the adaptor to (i) receive an elongate member through an opening in the body of the adaptor; and (ii) receive a fluid delivered through a secondary access tube of the adaptor. The secondary access tube requires space for storage and use in addition to the space required by the longitudinal body of the adaptor.
Furthermore, it is often desirable to selectively, temporarily affix a medical instrument such as a guidewire or a catheter to a valve during a medical procedure. Loose, sliding instruments can be inadvertently moved within or withdrawn from a desired location within a patient""s body. A number of different methods are available for selectively affixing medical instruments within an adaptor.
In one effort to selectively affix a wire to a desired location within a valve, a flow switch is employed. The flow switch has (i) an open position in which fluid or a wire can pass through the switch; and (ii) a closed position which does not permit fluid flow or wire movement. The closed position is achieved through the use of a roller clamp. However, upon clamping a wire in a fixed position through the use of the roller clamp, it is possible to permanently bend or crimp the wire. Typical guide wires and other medical grade wires are delicate, thin elongate instruments and are readily subject to such crimping and bending when used in conjunction with such a clamp, which can significantly hamper the practitioner""s ability to use the instrument.
There is therefore a need in the art for a space efficient, reliable hemostasis valve which can selectively maintain a wire such as a guidewire in a desired position without crimping the wire and without allowing blood loss through the valve.
It is therefore an object of the present invention to provide an improved hemostasis valve.
It is another object of the present invention to provide a space efficient hemostasis valve.
It is another object of the present invention to provide a hemostasis valve which minimizes the loss of body fluids during insertion, repositioning, or removal of medical instruments, such as catheters and guide wires, from the hemostasis valve.
It is another object of the present invention to provide an improved hemostasis valve that is capable of being opened to allow fluid to pass therethrough without fluid leaking from the hemostasis valve.
It is another object of the present invention to provide a hemostasis valve which is configured for high pressure injections through the valve.
It is another object of the present invention to provide a hemostasis valve which does not leak during high pressure injections through the valve.
It is a further object of the present invention to provide an improved hemostasis valve which can selectively affix a wire such as a guidewire within the valve without permanently bending or crimping the wire.
It is a further object of the present invention to provide an improved hemostasis valve which can selectively serve as a handle, steering device or torquing device for a wire or other elongated medical instrument.
Still another object of the invention is to provide a hemostasis valve having a substantially linear configuration.
Still another object of the present invention is to provide an improved hemostasis valve that enables the insertion, repositioning or removal of a catheter or guide wire with increased speed and substantially without the loss of body fluids.
Still another object of the invention is to provide an improved valve system for selectively coupling to an elongate instrument such as a wire and/or a fluid delivery means.
To achieve the foregoing objects, in accordance with the invention as embodied and broadly described herein, a hemostasis valve apparatus is provided that is adapted for accessing the cardiovascular system of a patient. A hemostasis valve apparatus of the present invention comprises: (i) a valve body; (ii) a first resiliently deformable seal disposed within the valve body; and (iii) a plunger movably coupled to the valve body so as to selectively open and close the seal.
The valve body and the plunger each have a lumen therethrough. The valve body lumen has a distal valve opening and the plunger lumen has a proximal valve opening. The plunger is movably coupled to the valve body such that a passageway extends from the distal valve opening to the proximal valve opening through the lumens of the plunger and valve body.
The first seal includes a longitudinal flow path therethrough which communicates with the lumen of the valve body when the first seal is in an open position. The first seal assumes a normally open position when not subjected to a compressive force by the plunger, but responds to a compressive force by the plunger to reduce the size of the flow path. When a compressive force is exerted on the compressible seal, a portion of the compressible seal moves radially inward to form a progressively tighter seal. The amount of compressive force that is being exerted on the compressible seal can be incrementally adjusted so as to selectively and progressively reduce the size of the flow path.
The resiliently deformable seal can couple a delicate medical instrument such as a guidewire, occluding wire, or other wire, in a fixed position within the valve without crimping or otherwise damaging the medical instrument.
The resiliently deformable seal sits within a compression chamber of the valve body. The plunger is configured to selectively exert compressive force on the first seal, either through direct contact or indirect contact. By moving back and forth between first and second positions with respect to the valve body, the plunger selectively opens and closes the first seal.
A second seal seals the passageway extending from the distal valve opening to the proximal valve opening through the lumens of the plunger and valve body. The second seal thus prevents fluid from flowing out of a location intermediate the proximal and distal valve openings. In one embodiment, the second seal comprises a resilient O-ring disposed about the distal end of the plunger, which is inserted within the valve body. The O-ring abuts the interior surface of the valve body, sliding along the interior surface of the valve body as the plunger is moved back and forth within the valve body. Preferably, the O-ring is located within an annular groove within the distal end of the plunger.
A connector, e.g., a Luer connector, is coupled to the proximal end of the plunger for coupling a fluid delivery means for delivering fluid in fluid communication with the passageway of the valve. The proximal connector on the plunger, combined with a resiliently deformable first seal provides a unique, reliable, efficient valve for selectively (i) injecting fluid through the valve; and/or (ii) coupling a delicate, elongate instrument to the valve.
The valve body comprises an elongate tubular body which preferably has a solid tubular body wall extending from a proximal end of the tubular body to a distal end of the tubular body. Since the plunger has a connector for coupling to a fluid delivery means, the valve body does not require the use of a secondary fluid access tube extending from the valve body, as with typical adaptors having hemostasis valves. Consequently, the valve is not required to have a xe2x80x9cYxe2x80x9d or xe2x80x9cTxe2x80x9d configuration, but can feature a substantially linear configuration, i.e. substantially straight, which is convenient for storage and use.
The plunger also comprises a tubular body which preferably has a solid tubular body wall extending from a proximal end of the tubular body to the distal end of the tubular body. The plunger and valve body each further comprise at least one and preferably a plurality of wings extending from each tubular body.
The second seal withstands significant fluid pressure by sealing the passageway defined by the plunger and valve bodies. The second seal seals the passageway even when the first seal is in the open, uncompressed position and the valve is coupled to a fluid delivery means. Thus, the valve apparatus of the present invention is particularly useful for high pressure fluid injections in which a fluid delivery means is coupled to the proximal end of the plunger and fluid is injected through the plunger and an opened, uncompressed first seal. The valve apparatus of the present invention is thus advantageous over typical Touhy Borst type valves in which blood can escape through the threads of the valve when the seal of the valve is in an uncompressed position.
By way of example, the valve of the present invention can be used as (i) an adaptor coupled to an introducer which receives elongate instruments or fluid therethrough; (ii) a handle or steering device which grips a medical instrument and which is grasped by a practitioner as the instrument is oriented into a desired location; (iii) a torquing device designed to rotate an elongate member such as a coiled member affixed within the valve; (iv) a fluid injection adaptor for receiving high pressure injections therethrough; and/or (v) a variety of other uses.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.